Fuse



Sept. 5, 1939. s. R, sMrrH 2,172,226

FUSE

Filed Nov. lO, 1957 ggav sa' 36 3a' 'l////////////////l///////////////////q{{{{///////l Inventor: Sdneg Smith,

His Attorneg.

Patented Sept. 5, 1939 FUSE Sidney R. Smith, Lenox, Mass., assignor to General Electric Company, York Application November 10, 1937, Serial No.

16 Claims.

A further object is the device having a Weather-tight housing which and damage to the internal parts of the fuse device.

may be mounted.

Referring to the drawing, I0 designates an open-ended tubular casing of insulating material, is adapted to sure cap 24 which Its end of the casing and trally locatedopening through of the `right-hand connection lead M.

a corporation of New struction of Fig. 1 1s provided with a metal vc10- snugiy over the rights-hond has in its vend wall a`. cen- 25 for the passage theretoward the respective then operative normally to maintain the elements 20 and 26 under compression.

In the construction of Fig. 2, both ends of casing I0 are closed by means of disks 30 which have centrally located openings 3i for the outward extension therethrough of the connection leads I4 of the fuse link. These disks are relatively stii and preferably are comprised of brous insulating material although they may be comprised of metal. Surrounding the connection leads exteriorly of disks 30 are packing elements or washers 32 of deformable resilient material which are disposed within cup-shaped metal caps 33 snugly fitted respectively over the opposite ends of casing I0 and having openings in their end walls for the passage therethrough of the connection leads. A material such as soft spongy rubber is particularly suitable for the construction of the packing elements in the embodiment of Fig. 2 as well as in the other embodiments illustrated and described herein. In the assembly of the device of Fig. 2, the caps 33 are pressed inwardly with considerable force adjacent ends of casing IIJ so .as tocompress the packing elements l,or washers 32, and the caps 33 are then secured to the connection leads passing therethrough in any suitable manner as for example by soldering as indicated at 34. This compression of the packing washers by caps 33 results in deformation of the washers into moisture-tight sealing engage-` ment with the connection leads I4 passing therethrough and results also in moisture-tight sealing engagement between the adjacent faces of disks 30 and washers 32, disks 30 being at the same time pressed firmly against the ends of casing I0. The resultant expansive force of the packing washers against caps 33 imposes tension upon the portion of the fuse link within casing I0 and the tensioned fuse link is then operative 'to maintain the packing washers compressed.

In order to secure an even more effective weather-tight sealing of the fuse enclosing housing of the present invention, the packing elements or washers vmay `be disposed within casing I0 as in the constructions illustrated in Figs. 3 and 4. In both of these constructions there -is disposed within casing I0 an inner tubular casing 36 which is comprised of insulating material and which is shorter than casing I6 so that the outer ends of casing 36 are spaced inwardly from the adjacent cuter ends of casing I0, The

' inner casing may be slidable relative to the outer casing or may be fixed, as desired. The two packing elements or washers 31 of the device of Fig. 8 are disposed respectively at the opposite ends of the inner casing between disks 38 and closure caps 39. As will be seen from the drawing, the connection leads I4 of the fuse link extend respectively at vthe opposite endsv of casing I0 through the disks 38, packing washers 31, and end caps 39. End caps 39 have inwardly projecting annular ridges 4B arranged to bear against the outer faces of the packing washers. With the component parts of the device of Fig. 3 assembled as illustrated, end caps 39 `are pressed inwardly so that their outer rim portions press tightly against the respective opposite ends of casing I0 and the end caps are then secured to the connection leads passing therethrough in any suitable manner, as by soldering as 4indicated at 4i. Thus, the packing washers 31 are compressed between the disks 38 and the inwardly projecting ridges 40 of end caps 39 and the inner faces of the vpacking washers are forced into moisturetight sealing engagement with the outer faces of disks 38 around the centrally located openings 38' therein through which the connection leads extend. Also, the compression of the packing washers causes deformation thereof into moisture-tight sealing engagement with the connection leads extending therethrough and with the surrounding inner walls of casing I0. The portion of the fuse link within the fuse housing is subjected to tension by the expansive force of the packing washers against the end caps 39 and the tensioned fuse link portion serves to maintain the packing washers under compression.

The sealing of the left-hand end of casing III in the embodiment of Fig. 4 is accomplished in a manner similar to that just described in con-r nection with the embodiment of Fig. 3. However, a smaller packing washer 45 to toroidal shape is employed in the construction of Fig, 4 and this washer is compressed against the disk 46 at the left-hand end of inner casing 36 by means of an end cap 41 which has a round body portion fitting into the bore of casing I0 and which has also a peripheral ange 48 which bears against the left-hand end of casing I0. At the right-hand end of the device of Fig. 4 a similar form of disk 46, torodial packing washer 45, and end cap 41 are employed but a coil spring 50 is inserted between the right-hand disk 46 and the right-hand end of inner casing 36. In the assembly of the device of Fig. 4, the end caps 41 are pressed inwardly so that their flanged rims 48 press tightly against the opposite ends of casing I0, and thc outer ends of the fuse link terminal shanks I5 and I6 are then crimped or swaged around connection leads I4 in such manner that the shoulders 5I formed in the terminal shanks by the crimping or swaging engage the outer faces of the end caps 41 so as to hold these caps in place. Thus, the left-hand packing washer 45 is compressed between Vthe left-handend cap 41 and the disk 46 which bears against the left-hand end of inner casing 36, while the righthan`d packing washer 45 and spring 50 are compressed between the right-hand end cap 41 and the right-hand end of inner casing 36. The packing washers thereby are forced into moisture-tight sealingv engagement with the outer face of disks 46 around the openings therein through which the fuse link terminal shanks extend, and, due to their compression, are deformed into moisture-tight sealing engagement with the terminal shanks and with the surrounding inner walls of outer casing I0. As in the previously described embodiments, the expansive force of the packing washers against the end caps imposes tension upon the fuse link and the tensioned fuse link in turn maintains the packing washers under compression. The round crosssection of the toroidal packing washers 45 facilitatesdeformation and radial expansion thereof into sealing engagement with the fuse link terminal shanks and the inner walls of the outer casing. Spring 50 serves to maintain substantially constant tension on the fusible section of the fuse link regardless of any setting'V of the packing washers and of any creeping or stretching which may occur in the fusible section.

The constructions herenbefore described provide extremely low cost fuse units which may be supplied to operating companies for quick and easy installation on over-load lines in various' vconductors 55 and 56 are fastened to a strain inof the present invention are of such Weather-tight construction that they may be installed in any position without danger of entrance of moisture into the enclosing housings thereof to cause corrosion and damage of the interna] fuse parts.

dication of fuse operation.

As will be evident to one skilled in the art, the present invention is not limited to the specc details of the illust ated constructions.

before described sealing and closing Ameans may be employed in an individual device.

What I claim as new and desire to secureby Letters Patent of the United States is:

1. In a fuse device, the combination with a ,fuse link and an enclosing housing therefor having an normally maintaining-"said packing element moisture-tight with said opening. 5. In a fuse device, a housing, a fuse link havmoisture-tight sealing engagement with the wall of said housing 6. In a fuse compressed mentserving normally to maintain said fuse link under tension,

7. In a fuse device, a fuse link, means providing an enclosing housing for said link having an silient material pressed between element and operative fuse link.

8. In a fuse device, a tubular casing having an open end, a packing element of deformable resilient material in said casing adjacent said open end thereof, a tensioned fuse link in said casing having a portion extending through said element, and means utilizing the tension of said fuse link for normally maintaining said element compressed and in substantially moisture-tight sealing engagement with the surrounding walls of said casing.

9. In a fuse device, a fuse link, a housing therefor including an outer tubular casing and an inner tubular casing arranged within the outer casing with one end of the inner casing spaced inwardly from the corresponding' end of the outer casing, a packing washer comprised of deformable resilient material disposed within said outer casing intermediate the said ends of said two casings, said fuse link having a connection portion extending outwardly through said washer, a bearing cap connected with said connection portion of the fuse link exteriorly of said Washer for pressing against the exterior of the washer, and means including said link for effecting compression of said washer between said cap and the said one end of said inner casing to force the washer into substantially moisture-tight sealing engagement with the surrounding inner walls of said outer casing.

10. In a fuse device, a fuse link, means providing a housing therefor having. an opening for the outward extension of a connection portion of the fuse link, a packing'washer for said opening disposed around said connection portion and comprised of deformable resilient material, means including a coiled compression spring operatively connected for imposing tension on said fuse link and means cooperative with said spring for compressing said washer into subfor said opening normally comsaid abutment and said bearing to impose tension on said stantially moisture-tight sealing engagement terial in said casing at with the walls of said housing around said opening.

11. In a fuse device, a tubular casing having an open end, means providing an abutment in said casing spaced from said open end thereof, a helical spring in the casing intermediate said abutmentand said open end of the casing, a washer-like element of resilient deformable maone end of said spring, a fuse link in said casing having a portion extending outwardly through said washer-like element, and means utilizing the tension of said fuse link for maintaining said spring and said washer-like element compressed against said abutment with said washer-like element in substantially moisture-tight engagement with the surrounding inner walls of the casing.

12. In a fuse device for outdoor installation, a weatherproof tubular casing having openings respectively at opposite ends thereof, a fuse link in said casing having connection portions extending out respectively through said openings, means weather-tightly sealing the opening at one end of the casing around the fuse link con- 'nection portion extending therethrough, a compressed packing washer of deformable resilient material tightly surrounding. the other of said fuse link connection portions and weathertightly sealing the opening in the `other end of said casing through which said other fuse link connection portion extends, and means normally utilizing the expansive force of said compressed washer for imposing tension 13. In a fuse device, a housing, a fuse link having a fusible section in said housing and a stiff shank portion extending outwardly through an opening in said housing, a compressed packing member of resilient material surrounding said shank portion adjacent said opening for substantially moisture-tightly sealing the opening, and means including said compressed member tending to force said shank portion longitudinally outward to impose tension on the portion of said fuse link within the housing.

14. In a fuse device, a casing having an opening for discharge of gases therefrom, a tensioned fuse link having a fusible section in said casing, closure means for said opening including a packing of deformable resilient material, and means operative under the iniiuence of the tension of said fuse link to maintain said packing normally compressed in substantially moisturetight sealing relation to said opening, said closure means being releasable upon rupture of said fusible section to permit discharge of gases from said casing. 15. In a fuse device, a casing having an opening for discharge of gases therefrom, a fuse link having afusible section in said casing and a connection portion extending outwardly through said opening, means including a spring operative normallyto tension said fuse link, closure means for saidA openingincluding a packing of deformable resilient material in surrounding relation to said connection portion, under the influence of the tension of said fuse link to maintain said packing normally compressed in substantially moisture-tight sealing relation to said opening, said closure means being releasable upon rupture of said fusible section. to permit discharge of gases from said casing.

16. In a fuse device for outdoor installation, a weatherproof tubular casing, a fuse link having a fusible section in said casing and connection portions extending outwardly respectively through openings at opposite ends of the casing, means operative normally to tension said fusible section and operative upon rupture of the fusible section to effect relative movement apart of said connection portions and widening of the gap between tlre ruptured ends of the fusible section, means weather-tightly closing the opening at one end of said casing around the corresponding one of said connection portions and means providing a releasable weather-tight seal for the opening at the other end of theasing around the other of said connection portions, which said last means is releasable upon fuse operation tov permit discharge of gases from the casing.

SIDNEY R. SMlTH.

on said fuse link.

and means operative 

